A traditional method for cutting a circular plate with a gas burner needs a tool as shown in FIG. 1, a center post A combined with an arm having its end fixed with a base B. A circle has to be marked out on a metal plate with a compass, and then its center has to be marked with a point with a center punch, and on the point the tip of said center post A is placed. A gas burner is to be put into a hole in the base B to cut the circle marked on the plate by moving the base B along said marked circle with the post A functioning as the center. In the cutting process, the post A may move or slide away from the punched point so that the cut product may not have a correctly circular shape.